1. What is Percentage of Air Voids?

The Percentage of Air Voids in soil represents the proportion of air-filled spaces relative to the total volume of the soil mass. It is a crucial parameter in geotechnical engineering that helps assess soil compaction, permeability, and overall stability.

2. How Does the Calculator Work?

The calculator uses the Percentage of Air Voids formula:

Where:

• \( n_a \) — Percentage of Air Voids (%)
• \( e \) — Void Ratio (ratio of void volume to solid volume)
• \( S \) — Degree of Saturation (ratio of water volume to void volume)

Explanation: The formula calculates the percentage of air-filled voids by considering the void ratio and the degree of saturation, which indicates how much of the void space is occupied by water.

3. Importance of Air Voids Calculation

Details: Accurate calculation of air voids percentage is essential for evaluating soil compaction quality, drainage characteristics, frost susceptibility, and overall soil behavior under various loading conditions in construction and geotechnical projects.

4. Using the Calculator

Tips: Enter void ratio (e) as a positive decimal number (typically between 0.3-2.0 for most soils). Enter degree of saturation (S) as a decimal between 0 (completely dry) and 1 (fully saturated). All values must be valid and within reasonable ranges.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical range for air voids in compacted soil?
A: For well-compacted soils, air voids typically range from 5% to 15%, depending on soil type and compaction effort.

Q2: How does air voids percentage affect soil permeability?
A: Higher air voids percentage generally increases permeability as it provides more pathways for water and air movement through the soil.

Q3: What is the relationship between void ratio and porosity?
A: Porosity (n) = e/(1+e), where e is void ratio. Porosity represents the percentage of void space in total volume, while void ratio compares void volume to solid volume.

Q4: Why is degree of saturation important in air voids calculation?
A: Degree of saturation determines how much of the void space is occupied by water versus air, directly affecting the percentage of air voids.

Q5: Can air voids percentage be negative?
A: No, air voids percentage cannot be negative. It ranges from 0% (completely saturated or zero void ratio) to a maximum value that depends on the void ratio.